// this will be called when they keys need to be collected from the server
public async Task FetchExposureKeysFromServerAsync(ITemporaryExposureKeyBatches batches)
{
// This is "default" by default
var region = LocalStateManager.Instance.Region ?? DefaultRegion;
var checkForMore = true;
do
{
try
{
// Find next batch number
var batchNumber = LocalStateManager.Instance.ServerBatchNumber + 1;
// Build the blob storage url for the given batch file we are on next
var url = $"{apiUrlBlobStorageBase}/{blobStorageContainerNamePrefix}{region}/{batchNumber}.dat";
var response = await http.GetAsync(url);
// If we get a 404, there are no newer batch files available to download
if (response.StatusCode == System.Net.HttpStatusCode.NotFound)
{
checkForMore = false;
break;
}
response.EnsureSuccessStatusCode();
// Skip batch files which are older than 14 days
if (response.Content.Headers.LastModified.HasValue)
{
if (response.Content.Headers.LastModified < DateTimeOffset.UtcNow.AddDays(-14))
{
LocalStateManager.Instance.ServerBatchNumber = batchNumber;
LocalStateManager.Save();
checkForMore = true;
continue;
}
}
// Read the batch file stream
using var responseStream = await response.Content.ReadAsStreamAsync();
// Parse into a Proto.File
var batchFile = TemporaryExposureKeyBatch.Parser.ParseFrom(responseStream);
// Submit to the batch processor
await batches.AddBatchAsync(batchFile);
// Update the number we are on
LocalStateManager.Instance.ServerBatchNumber = batchNumber;
LocalStateManager.Save();
}
catch (Exception ex)
{
Console.WriteLine(ex);
checkForMore = false;
}
} while (checkForMore);
}
public Task FetchExposureKeysFromServerAsync(ITemporaryExposureKeyBatches batches)
{
throw new NotImplementedException();
}
